1. Field of the Invention
The present invention relates to a drop testing device, namely a fall impact apparatus, for testing the tolerance of a product against free fall impact.
2. Description of the Related Art
Portable electronic devices such as portable telephones, MD players, and electronic dictionaries have conventionally been tested for impact resistance using a fall impact apparatus in order to improve the reliability of such products.
In such fall impact apparatus, the test subject must be dropped in a free fall manner or as close to such free fall conditions as possible. When caused to free fall from a sufficiently high position, however, the test subject rotates during the free fall, and thus the site which collides with the surface cannot be kept constant. As a result, test results cannot be reproduced repeatedly.
In order to solve this problem, a fall impact apparatus using a hand-like shaped apparatus which is capable of releasably grasping the test subject is disclosed in Japanese Patent Application Laid-Open No. 2000-55778. This device comprises a position detection means for detecting that the test subject has fallen to a height at which the test subject is to be released from by the grasping of the hand-like shaped apparatus, and thus the test subject is released with good timing just before impact. By means of this construction, the attitudinal angle of the test subject is maintained until the moment of release.
Further, a method of dropping a test subject wherein the test subject is hung by a cord-form material is disclosed in Japanese Patent Application Publication Laid-Open No. 2000-65677. In this device, the test subject is held by the cord-form material until the moment of impact with a base.
However, in the aforementioned fall impact apparatus which comprises the hand-like shaped apparatus, the test subject falls freely for a short period of time following release from the apparatus, and thus change may occur in the attitudinal angle of the test subject. Moreover, a position detection means and a means for automatically releasing the test subject have to be provided, which tends to complicate the structure of the device.
In the dropping device which holds the test subject by a cord-form material, the cord-form material itself may swing or vibrate during the dropping process due to air resistance or the like, and hence the attitude of the test subject cannot be sufficiently maintained as the attitude originally set prior to starting the free fall action.
It is therefore an object of the present invention to provide a fall impact apparatus which is capable of fixing the attitudinal angle of a test subject during a drop test by free fall until the moment of impact with an impact surface.